AAARGH!! Problems with first lager fermentation

[Tippsy-Turvy]

I had been taking regular SG readings and the plot was indicating that my FG was going to be higher than originally forecast using Brewer's Friend, perhaps 1.011 for the FG compared with the software forecast of 1.007.

So, i started the D-rest early and now, after 5 days of d-resting, I tested the SG and it's 1.017 - not even close to the new target FG! The chart now suggests the FG might actually be ~1.016!?!

Is this a stuck fermentation? Should I repitch even though all I have is US-05 in the fridge? Or do I just go ahead and lager in the secondary as yeast attenuation estimates are just that, estimates?

To complicate matters, I threw in my dry hops on the second day of d-resting so they've been in there for 4 days already. Damn.

 

[Tippsy-Turvy]

FYI, i mashed at 147F, pitched 1 rehydrated packet of W34/75, 2.5 gallon batch, OG was 1.047 and began D-rest at 1.020-ish.

Grain bill:
74% Munich 10L
16% Vienna
7% Crystal 60L
3% Chocolate malt

 

[bigdaddybrew]

Give the fermenter a swirl to roust the yeast and leave it at room temp. Hopefully it will finish. A week or two is not too long.

 

[beersk]

1.017 certainly isn't bad. With that grain bill, that may be all it comes down to. How long did you mash at 147F? How do the samples taste? I don't think I'd call 1.017 a stuck fermentation. Give it another week and if it doesn't come down more, it's done. It'll taste good still I'm sure.

 

[Tippsy-Turvy]

1.017 certainly isn't bad. With that grain bill, that may be all it comes down to.

Cross my fingers and toes that you're right. It's just that I entered every detail into Brewer's Friend and it's never been so wrong before on the FG estimate.

The mash was an attempt at a Kesselmaische single-step decoction. So:
1) S-rest at 147F for 35mins
2) Separately boil grains for 20mins
3) Re-combine, leave at 158F for 20mins
4) Dunk sparge for 10mins

The samples tasted nice actually! Perhaps a tiny sweet but I've no problems with that as I like my IBUs low.

I'll give it a gentle stir like Bigdaddy suggested, raise the temp a little and leave it for a few days more. The problem now is that the dry hops will have been in there for over a week so i'd better expect grassy flavors to develop. Oh well, live and learn.

Thanks everyone.

 

[Gavin C]

One or two things may be contributing to this but I am no expert when it comes to lagers. Just a beginner myself.

I'm guessing you are using a conventional grain crush suitable for a mash-tun with false bottom or braid.

If that is the case your rest at 147 for 35mins may be a little short. Perhaps not.

Did you test the mash for conversion prior to pulling the decoction? Did you carry out a sacch. rest on the decoction itself to ensure conversion prior to raising it to boiling?

What was your mash efficiency?

I'm not familiar with the specific name on your mash profile so forgive my ignorance if all those steps are implied when one uses this type of mash.

Just throwing ideas out there. Hopefully someone more knowledgable (that includes you OP) will correct me if I'm way off base.

 

[Tippsy-Turvy]

Good to have your input, Gavin.

Let's see. Mash duration could have been longer. I've tried this Kesselmaische approach twice before and hit my FG each time but those occasions also required a p-rest unlike this one. Does mash duration also affect FG? I always thought it only affected OG. Too many G's, OMG.

Conversion seemed fine as the mash ph was 5.3 and the sample was nice and sweet. The decoction was pulled from this same mash so its conversion should have been the same(?). Brewhouse efficiency was 85%.

I'm starting to lean towards the idea that the grain bill might be responsible but then the software knew this in its FG calculation.

Hmm. Let's see if the swirl and wait approach helps.

 

[Gavin C]

All sounds like things went really well. Recipe looks good.

I'm all out of ideas.

 

[Tippsy-Turvy]

You know what. It must be a yeast health issue if extraction was fine and temperatures were fine.

I shake vigorously to aerate but always only for ~20 seconds as that's all I need to completely fill the head space with foam. Whilst that might work for ales (even then, I probably could shake longer ) perhaps I need to shake much longer for lagers? That might explain why I had no krausen! If so, perhaps I should pick up another packet of W34/75 and pitch it asap.

 

[Gavin C]

You could also look at an oxygenation setup. Not sure if it makes much of a difference. Each of my batches gets 2 mins of pure O2.

I'm not a fan of shaking 5.5 gallons of wort. I'm lazy and want to protect my back.

Oxygenation setup.

 

[ZebulonBrewer]

With your grain bill being mostly Munich and Vienna, 1.017 certainly isn't bad; there are a bunch of unfermentable sugars in there. I would go ahead and lager it.

 

[Tippsy-Turvy]

I'm adding an aeration set up to my growing Santa wish list and given how important aerating is (and my back), it's going in ahead of the Speidel fermenter.

Yup, I'll just lager this batch. At worst, it'll be another addition to my learning experience

Much obliged everyone!

 

[Cyclman]

Could be lots of things, I would do a fresh starter, oxygenate the heck out of it right before pitching at high kraeusen.

 

[Tippsy-Turvy]

Could be lots of things, I would do a fresh starter, oxygenate the heck out of it right before pitching at high kraeusen.

That would have been the smart thing to do! I didn't have any more W34/75 so I just went ahead and lagered it. Oxygenation seems to be my problem and my next challenge.